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<p>[QUOTE=&quot;Leadfoot, post: 1335137, member: 2972&quot;]Again, the (primary) reason part of the coin is not in focus is because it is not perfectly parallel to the camera.</p><p><br /></p><p>The reason you don&#039;t see it so much in smaller coins is because all things being equal the coin is &quot;off&quot; more in the larger example.&nbsp; </p><p><br /></p><p>The &quot;curve&quot; of the lens has nothing to do with it.</p><p><br /></p><p>There are two easy ways to solve the problem, otherwise you&#039;ll continue to battle it....&nbsp; First you can use a level (a simple bubble level will due) to level your table, then do the same to your camera.&nbsp; Vertically or horizontally both work, depending on your setup.&nbsp; &nbsp; The other way to solve it is to buy a copy stand (that has a fixed base and telescoping camera mount).&nbsp;&nbsp; I suppose a third way would be to &quot;eye&quot; it, but that will not be consistent or repeatable like the two former examples.&nbsp; Lastly, increasing the f-stop (i.e. decreasing aperature) will help, but not solve the problem.</p><p><br /></p><p>Personally I use a tripod and bubble level -- and with some practice you can get even the largest coins perfectly sharp from edge to edge:</p><p><br /></p><p><img src="http://www.pbase.com/miker/image/49821202/original.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p>Hope this helps...Mike</p><p><br /></p><p>p.s. the other factor that causes your photo to be out of focus is the depth of field.&nbsp; Specifically DoF is very &quot;thin&quot; causing any angular difference between the plane of the coin and the plane of the sensor to result in an out of focus subject.&nbsp; Depth of field is dependent on two further factors -- magnification factor (a function of subject distance and lens focal length) and aperture (larger aperture (i.e. lower f number) = thinner focal plane, smaller aperture (i.e. higher f number) = thicker focal plane).&nbsp; You can read more about depth of field here: <a href="http://en.wikipedia.org/wiki/Depth_of_field" target="_blank" class="externalLink ProxyLink" data-proxy-href="http://en.wikipedia.org/wiki/Depth_of_field" rel="nofollow">http://en.wikipedia.org/wiki/Depth_of_field</a>&nbsp; You can also get a good book on coin photography here: <a href="http://www.amazon.com/Numismatic-Photography-2nd-Mark-Goodman/dp/193399004X" target="_blank" class="externalLink ProxyLink" data-proxy-href="http://www.amazon.com/Numismatic-Photography-2nd-Mark-Goodman/dp/193399004X" rel="nofollow">http://www.amazon.com/Numismatic-Photography-2nd-Mark-Goodman/dp/193399004X</a></p><p><br /></p><p>p.p.s. just wait until you try and take a photo of a coin in a slab slightly tilted, and none of the above methods work and you have to go back to your &#039;eye&#039;.&nbsp; <img src="styles/default/xenforo/clear.png" class="mceSmilieSprite mceSmilie2" alt=";)" unselectable="on" unselectable="on" />[/QUOTE]</p><p><br /></p>

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